A Group One race will hang in the balance on Thursday nearly a week after the runners crossed the line following confirmation that last Friday's controversial renewal of the Falmouth Stakes, in which Elusive Kate beat Sky Lantern by a neck, will be the subject of an appeal by the connections of the runner-up.

Elusive Kate drifted left through much of the final quarter of the one-mile event, and William Buick, her jockey, also appeared to unintentionally strike Sky Lantern, the 4-7 favourite, on the head with his whip. Following an inquiry into the outcome by the Newmarket stewards, which was televised live on Channel 4, the result was allowed to stand.

"So many people have rung urging us to appeal and insisting that we have a strong case, so we have decided to give it a shot," Richard Hannon, the trainer of Sky Lantern, said on his website on Monday.

"We have spoken to [Sky Lantern's owner] Ben Keswick and, though originally we were taking the decision on the chin, we have backtracked and decided to go ahead with the appeal."

Bets on the race were settled on the day, but a change in the official finishing order could have an impact on Hannon's close race with Aidan O'Brien for the trainers' championship, because the Falmouth was worth £102,078 to the winner but only £38,700 to the runner-up. A reversal of the placings would also deny John Gosden, the current champion trainer, his first Group One success of the season.

The Hannon stable has already recorded three Group One wins this year, with Havana Gold, in the Prix Jean Prat, adding to Sky Lantern's victories in the 1,000 Guineas and Coronation Stakes.

Whatever the outcome of Thursday's appeal, the yard will target another success at the highest level at Glorious Goodwood in two weeks' time, when Toronado will renew his rivalry with Dawn Approach in the Sussex Stakes, the feature race of the meeting.

Dawn Approach has beaten Toronado in the 2,000 Guineas and the St James's Palace Stakes this year, but there was just a short-head between the pair in the latter race, in which both colts suffered interference in running.

"I'm not saying we're going to beat him, but we're fully entitled to go there and take him on again," Richard Hannon Jr, his father's assistant, said on Monday at a launch event for Glorious Goodwood.

"We felt we were slightly unlucky [at Ascot], I thought we came there to beat him and to his credit he stayed on and beat us. Toronado didn't run his race at all in the Guineas but he put that to bed at Ascot. If there's the same distance between them at Goodwood it will be awesome."

Jim Bolger, Dawn Approach's trainer, said that his colt has recovered well from his hard race at Ascot. "He was bucking and squealing two days afterwards so it didn't take anything out of him," Bolger said.

"I'd prefer a level track [to the undulations of Goodwood] but it's the same for everybody. Good, safe ground is always best for any horse because they last for longer, so I'd be hoping that the ground is good as usual."

Brian Toomey, who suffered life-threatening injuries in a fall at Perth this month, is continuing to make progress in his recovery, a bulletin from the Injured Jockeys' Fund said on Monday.

"I spoke to Marian Toomey, Brian's mother, earlier today," Lisa Hancock, the chief executive of the IJF, said, "and she reported that Brian made good, steady progress over the weekend and remains in a stable condition."